Prolonged Survival and Risk Factors for Reintervention After Inflatable Penile Prosthesis Implantation

24% of patients required reintervention over a median 39-month follow-up; median prosthesis survival was 7 years, but no independent risk factors were confirmed.

Journal: The Canadian Journal of Urology | Published: 2026-02-28 | Type: Retrospective cohort | PMID: 41800513 Authors: Zouari S, Barthe F, Morrone A, et al. (Pasteur 2 Hospital / Université Côte d'Azur, Nice; Clinique Saint-Jean, Cagnes-Sur-Mer) Funding/COI: Funding not reported. Authors declare no conflicts of interest.

Summary

Among 137 men who received an inflatable penile prosthesis (IPP) at a single French center between 2014 and 2022, nearly one in four eventually required reintervention — either revision or explantation. Univariate analysis flagged smoking, older age, prior implantations, and intraoperative downsizing as potential risk factors. However, none of these held up in the multivariate Cox model, meaning the study cannot identify an independent predictor of failure.

Claims

• 33 of 137 patients (24.1%) required reintervention; 24 (17.5%) had revisions, 9 (6.6%) had explantations
• Median survival without reintervention: 7 years
• Median follow-up: 39 months (IQR 9–62)
• Downsizing (cylinder size reduction during surgery) associated with reintervention in univariate analysis (p = 0.046)
• Smoking associated with explantation in univariate analysis (p = 0.003)
• Older age associated with explantation (p = 0.034)
• Higher number of prior implantations associated with prosthesis revision (p = 0.009)
• Multivariate Cox model: no independent predictive factors identified

Study Quality

This is a retrospective, single-center study — the weakest observational design for identifying risk factors. The wide IQR on follow-up (9 to 62 months) indicates highly variable observation periods, which inflates uncertainty in time-to-event analyses. With only 137 patients and 33 events, the study is almost certainly underpowered for multivariate Cox regression; finding signals in univariate analysis that then vanish in the multivariate model is a textbook symptom of this problem, not a finding worth building clinical conclusions on.

The primary outcome (survival without reintervention) is clearly defined. Kaplan-Meier and Cox modeling are appropriate tools. But the small sample size means the model cannot reliably adjust for confounders, and the authors acknowledge no independent predictors were confirmed.

Red Flags

• Underpowered for multivariate analysis: 33 events across a Cox model with multiple covariates is insufficient — typically ≥10 events per predictor variable is required
• Retrospective design at a single center limits generalizability and introduces selection bias
• Wide follow-up IQR (9–62 months) suggests incomplete follow-up; patients implanted in 2022 had little time to fail
• Univariate signals didn't survive multivariate adjustment — the headline risk factors (smoking, age, downsizing) remain unconfirmed
• Funding not reported — unclear if institutional resources or industry support played a role
• No patient-reported outcomes (satisfaction, sexual function) reported

Strengths

• Up to 8 years of real-world follow-up captures late failures that shorter studies miss
• Clearly defined, clinically meaningful primary outcome
• Includes both mechanical failure and infection as endpoints
• Authors are appropriately cautious in their conclusions — they don't overclaim the univariate results

Verdict

This paper documents a reasonable real-world reintervention rate (24% over ~3 years median follow-up, 7-year median survival) consistent with existing IPP literature, but it cannot do what it set out to do: identify independent risk factors. The sample is too small, the follow-up too uneven, and the multivariate model too sparse. The smoking–infection signal is biologically plausible and worth investigating in a larger cohort, but this study alone doesn't establish it. File this as hypothesis-generating background data, not evidence that changes practice.